The present invention relates to a valve and to a method of manufacturing same, and particularly to a ventilation valve for valving air entry into or air exit out of the passenger compartment of a motor vehicle. The valve includes a housing and at least one closing flap which rests against crosspiece elements when closed and which is connected with the housing over a supporting area. The invention finds application in conjunction with valving air flow in motor vehicle passenger compartment ventilation systems, and will be described with particular reference thereto. However, it is to be appreciated that the present invention is also amenable to a wide range of other like applications.
The prior art German laid-open application DE 40 23 190 A1 teaches a return air blocking unit for use in conjunction with exiting ventilation of a passenger compartment of a motor vehicle. The closing flap is directly connected with the housing and includes a tongue which is firmly engaged in an aperture of the housing. In another embodiment of said prior art, a film hinge connection between the housing and the closing flap is formed during assembly by folding the closing flap around the film hinge.
German patent specification DE 40 02 052 C2 and German laid-open application DE 35 03 600 A1 teach additional air exit ventilation housings for motor vehicles wherein the closing flaps have lip edges which are connected in a non-displacable manner with the housing by means of a separate plug or pin.
The present invention contemplates an improved ventilation valve and method for manufacturing same whereby significant reduction in cost of parts and cost of manufacture is achieved.
In accordance with one aspect of the present invention, a valve comprises a housing and a closing flap. The housing and closing flap are produced by a two-component injection molding process. The housing is formed from a hard material, while in contrast the flap is formed from a softer material. A supporting area of the closing flap and/or an area of the housing which interacts therewith includes at least one retaining profile which engages at least one recess. Manufacturing of the housing using a hard material with subsequent injection of the closing flap using a softer material is preferably done using a single molding tool. Undesirable adhesion or bonding of the two components at the contacting surfaces is prevented while the connection between the closing flap and the housing takes place only in the supporting region. This results in significant cost reduction by eliminating the installation of the closing flap at the housing.
In accordance with another aspect of the present invention, the supporting region of the closing flap preferably has at least one retaining profile embedded in a recess of the housing. According to another configuration according to the invention, the supporting region of the closing flap is provided with retaining profiles on both opposite sides, with at least one retaining profile engaging a recess in the housing. The retaining profiles are preferably diagonally opposed.
In accordance with yet another aspect of the present invention, the fastening region of the housing is provided with a passage slot. The supporting region of the closing flap extends at least partially through the slot. Adjacent the passage slot, the housing is equipped with at least one recess and/or one retaining profile for engaging a corresponding opposite retaining profile and/or a recess of the supporting region of the closing flap.
According to still yet another aspect of the present invention, the closing flap is connected only in its supporting region with one side of the housing. Beyond that connection, both material components, in spite of the closing flap being supported by the crosspieces of the housing, have no adhesion with each other in the closed state. The two material components are also manufactured in said position.
According to an additional embodiment of the present invention, the supporting region of the closing flap includes a first projecting retaining profile disposed behind the passage slot which engages a recess of the housing. A second, inwardly oriented, retaining profile is disposed diagonally opposite the first projecting retaining profile and abuts an edge of the housing.